Tram system and methods for autonomous takeoff and landing of aircraft

ABSTRACT

One variation of a tram system includes: a chassis; a latch configured to selectively engage a latch receiver mounted to an aircraft; an alignment feature adjacent the latch and configured to engage an alignment receiver mounted to the aircraft and to communicate acceleration and braking forces from the chassis into the aircraft; an optical sensor facing upwardly from the chassis; a drivetrain configured to accelerate and decelerate the chassis along a runway; and a controller configured to detect an optical fiducial arranged on the aircraft in optical images recorded by the optical sensor adjust a speed of the drivetrain to longitudinally align the alignment feature with the alignment receiver based on positions of the optical fiducial detected in the optical images, trigger the latch to engage the latch receiver once the aircraft has descended onto the chassis, and trigger the drivetrain to actively decelerate the chassis during a landing routine.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a continuation application of U.S. patentapplication Ser. No. 17/039,749, filed on 30 Sep. 2020, which is acontinuation application of U.S. patent application Ser. No. 16/028,353,filed on 5 Jul. 2018, which is a continuation application of U.S. patentapplication Ser. No. 15/705,248, filed on 14 Sep. 2017, each of which isincorporated in its entirety by this reference.

TECHNICAL FIELD

This invention relates generally to the field of aerospace and morespecifically to a new and useful tram system and methods for autonomoustakeoff and landing of aircraft in the field of aerospace.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A and 1B are schematic representations of a tram system;

FIGS. 2A and 2B are schematic representations of one variation of thetram system;

FIG. 3 is a schematic representation of one variation of the tramsystem;

FIG. 4 is a flowchart representation of a method; and

FIG. 5 is a flowchart representation of one variation of the method.

DESCRIPTION OF THE EMBODIMENTS

The following description of embodiments of the invention is notintended to limit the invention to these embodiments but rather toenable a person skilled in the art to make and use this invention.Variations, configurations, implementations, example implementations,and examples described herein are optional and are not exclusive to thevariations, configurations, implementations, example implementations,and examples they describe. The invention described herein can includeany and all permutations of these variations, configurations,implementations, example implementations, and examples.

1. Tram System

As shown in FIGS. 1A and 1B, a tram system 100 (hereinafter a “tram100”) includes: a chassis 110; a latch 130; an alignment feature 132; afirst optical sensor 150; a drivetrain 120; and a controller 160. Thelatch 130 is coupled to the chassis 100 and is configured to selectivelyengage a latch receiver mounted to an underside of a fuselage of anaircraft. The alignment feature 132 is: adjacent the latch 130;configured to selectively engage an alignment receiver mounted to theunderside of the fuselage of the aircraft; and configured to communicateforces parallel to an anteroposterior axis of the chassis 100 into theaircraft. The first optical sensor 150 faces upwardly from the chassis100 and is configured to record a first sequence of optical images. Thedrivetrain 120 is configured to accelerate and decelerate the chassis100 along a runway. The controller 160 is configured, during a landingroutine, to: detect a first optical fiducial arranged on the aircraft inthe first sequence of optical images recorded by the first opticalsensor 150; adjust a speed of the drivetrain 120 to longitudinally alignthe first alignment feature 132 with the first alignment receiver on theaircraft during descent of the aircraft toward the runway based onpositions of the first optical fiducial detected in the first sequenceof optical images; trigger the latch 130 to engage the latch receiver onthe aircraft in response to descent of the first alignment receiver ontothe first alignment feature 132; and trigger the drivetrain 120 toactively decelerate the chassis 100 and the aircraft in response toengagement of the latch 130 on the latch receiver.

2. Applications

Generally, the tram 100 can operate at an airport to autonomously:actively “catch” an aircraft on its dorsal side as the aircraftapproaches a runway during a landing routine, as shown in FIG. 4 ;decelerate the aircraft to a taxiing speed; taxi the aircraft—supportedon its dorsal side—to a gate for unloading and loading; navigate back tothe head of the runway in preparation for a takeoff routine, as shown inFIG. 5 ; and then accelerate the aircraft to a takeoff speed beforereleasing the aircraft during a takeoff routine, as shown in FIG. 5 . Inparticular, the tram 100 can define a ground-based support vehicle forairport operations to autonomously assist aircraft during takeoff,landing, and taxiing, including assisting the aircraft: in acceleratingalong a linear runway during takeoff; coupling to the ground anddecelerating during landing; and reaching an assigned gate when taxiingthrough the airport.

The tram 100 can interface with passenger aircraft to assume powersupply requirements to accelerate the aircraft during takeoff and toassume power dissipation requirements during landing. For example, thetram 100 can include a set of electric motors delivering 10,000horsepower through ground- or rail-based wheels, and the tram 100 cansource electrical energy to power these electric motors from a localpower grid (i.e., “the grid”) via a power rail running along the runway.During a takeoff routine, the tram 100 can boost power available to theaircraft to accelerate to its takeoff speed, thereby reducing: fuelconsumption by the aircraft during takeoff; a necessary pre-flight fuelload in the aircraft; takeoff weight of the aircraft; and total energyconsumption for the aircraft to become airborne. Furthermore, becausetypical aircraft require 100% thrust (and 100% fuel consumption) attakeoff but only 70% of maximum thrust (e.g., and ˜70% of maximum fuelconsumption) during cruise, the tram 100 can enable the aircraft toachieve takeoff and cruise metrics similar to those of typical aircraftbut with smaller (e.g., lower maximum thrust) engines tailored forcruise efficiency—rather than compromised for both cruise and takeoffthrust requirements—by supplying additional power to accelerate theaircraft during takeoff. With engines now better tailored for cruiseefficiency, the aircraft may exhibit greater fuel (or energy) efficiencyduring cruise. In light of reduced engine size and energy consumptionduring takeoff and cruise, the aircraft can include smaller fuel tanks,require smaller fuel loads to cover a particular distance, and thusdefine a smaller overall package, which yields further fuel and materialefficiency gains. Because the aircraft is smaller, lighter, and containsengines yielding reduced maximum thrust, structural and mechanicalsystems in the aircraft can also be paired down in size and weight,thereby reducing product and maintenance costs for the aircraft.

The tram 100 “catches” the aircraft during a landing routine, carriesthe aircraft to its gate for unloading and loading, and then returns theaircraft to the runway and cooperates with the aircraft to accelerate toits takeoff speed without the aircraft (necessarily) contacting theground. Because the tram 100 interfaces the aircraft with the ground,the aircraft can omit landing gear entirely or can include low-use orsingle-use landing gear (e.g., skid plates) only, such as for emergencylandings exclusively. Weight of the aircraft can therefore be reducedthrough omission or simplification of landing gear, thereby improvingfuel efficiency, reducing production cost, and/or increasing carryingcapacity of the aircraft. Furthermore, less frequent or no use oflanding gear in the aircraft can reduce need for redundancies in sensorsand actuators for landing systems in the aircraft, reduce strength andload-carrying requirements of mounting locations for landing gear in theaircraft, such as to combat fatigue from repeated load cycles duringtakeoff and landing, thereby further reducing weight and production costof the aircraft. By carrying the load of the aircraft across a cradle140 and including systems to damp descent of the aircraft onto the tram100, the tram 100 can also yield improved comfort for passengers in theaircraft during takeoff and landing.

As described below, the tram 100 can source power from the grid—via apower rail running along the runway—to accelerate the aircraft duringtakeoff; the tram 100 can also implement regenerative braking techniquesand dump energy recuperated while decelerating the aircraft during alanding routine back into the grid via the power rail, thereby improvingtotal efficiency of the aircraft and airport systems from takeoff tolanding and reducing operational costs for the aircraft, the airport,and/or for airlines. The tram 100 can additionally or alternativelydissipate energy into a local energy storage system—such as a battery,flywheel, or hydraulic energy storage system integrated into the tram100 or arranged under the tarmac and connected to the power rail—duringa landing routine and then extract this energy back out of the onboardenergy storage system during a subsequent takeoff routine. The tram canalso supply power the aircraft while taxiing and/or while docked at aterminal, thereby eliminating a need for an auxiliary power generatoronboard the aircraft.

The tram 100 can also interface with a power rail to power itsdrivetrain and run along a set of locating rails—distinct from orphysically coextensive with the power rail—along a runway. By runningalong locating rails rather than a paved runway, the tram 100 can alsoenable elimination of tarmac at airports, which may further reduceconstruction, maintenance, and operating costs for the airport, such asby reducing or eliminating a need for runway deicing or clearing in coldand wet weather.

As described below, the tram 100 can interface with a remote computersystem, such as an autonomous flight controller 160, to supportautonomous takeoff, landing, and taxiing of aircraft at airports. Inparticular, passenger aircraft may implement autopilot techniques tonavigate toward a destination while airborne. However, limitedpositional accuracy of geospatial location systems and varyingconditions (e.g., wind directions and speed) near the ground may limiteffectiveness of autopilot techniques to manage takeoff and landing ofpassenger aircraft. However, the tram 100 can interface with the remotecomputer system and/or the aircraft directly to track the geospatiallocation of the aircraft via a geospatial location sensor in theaircraft as the aircraft approaches the tram 100; as the locationaccuracy limit of the geospatial location sensor in the aircraft arereached, the tram 100 can transition to implementing computer visiontechniques to track the position of the aircraft (e.g., fiducialspositioned on the aircraft) relative to the tram 100 until the tram 100engages and mechanically locks onto the aircraft. The tram 100 can alsointerface with a rail or other mechanical positioning structure on theground to maintain a longitudinal position of the aircraft along arunway, even in the presence of changing ground conditions (e.g.,crosswinds). The tram 100 can therefore cooperate with the remotecomputer system and the aircraft to achieve autonomous scheduling,taxiing, takeoff, cruise, and landing for aircraft, thereby furtherreducing operational costs of the aircraft over time.

The tram 100 is described herein as operated at an airport inconjunction with medium and large passenger airplanes. However, the tram100 can additionally or alternatively be operated on a commercial orfreight runway, a military base, an aircraft carrier, a small or privateairport or runway, etc. in conjunction with private, passenger, freight,and/or military airplanes of any other size or type.

3. Chassis and Fairing

The chassis 100 functions to locate the drivetrain 120 and to supportvarious subsystems of the tram 100, including the latch 130, alignmentfeature 132, sensors, controller 160 and fairings 112. For example, thechassis 100 can include a welded steel frame or monocoque steel,aluminum, or composite structure

The chassis 100 can also be clad in aerodynamic fairings 112, such asmetal or composite panels, to limit a drag coefficient of the tram 100and to reduce lift at aircraft landing and takeoff speeds. The chassis100 can also include ground effects structures that yield increasingdownforce as the tram 100 accelerates to takeoff and landing speeds,thereby sucking the tram 100 to the ground and resisting lift off theground by the aircraft during both takeoff and landing routines. Forexample, the tram 100 can include: Venturi tunnels extending along theunderside of the chassis 100 and configured to induce a pressure dropbetween the underside of the tram 100 and the ground from the front ofthe tram 100 to the rear of the tram 100, thereby drawing the tram 100down to the ground; a front inverted airfoil at the front of the tram100 (e.g., over the front axle of the drivetrain 120) to smooth airflowtoward the rear of the tram 100 and to increase load on the front of thetram 100 as the speed of the tram 100 increases; and a rear invertedairfoil at the rear of the tram 100 (e.g., over the rear axle of thedrivetrain 120) to increase load on the rear of the tram 100 as thespeed of the tram 100 increases. However, the chassis 100 can includefairings 112 or ground effects structures of any other type or form inorder to: smooth airflow over the tram 100 at speed (e.g., to reduceturbulence that may otherwise disturb the aircraft as the aircraftapproaches the tram 100 during a landing routine); and to yieldincreased downforce (i.e., inverse lift) on the tram 100 as the speed ofthe tram 100 increases to counter lift by the aircraft's wings duringtakeoff and landing routines.

4. Drivetrain

The drivetrain 120 is configured to accelerate and decelerate thechassis 100 along a runway. Generally, the drivetrain 120 is configuredto output sufficient mechanical power in the forward direction toaccelerate to and maintain a landing speed of a passenger aircraftwithin a limited distance (e.g., a “pre-runway” length of one-quarter ofa mile) during a landing routine. The drivetrain 120 is similarlyconfigured to output sufficient mechanical power in the forwarddirection—in cooperation with engines integrated into the aircraft—toaccelerate the aircraft to a takeoff speed within a length of a runwayduring a takeoff routine. The drivetrain 120 is also configured torapidly dissipate or transform kinetic energy to assist deceleration ofthe aircraft within the length of the runway during a landing routineand to slow the tram 100 following release of the aircraft during atakeoff routine.

4.1 Motive Force

In one variation shown in FIG. 1A, the tram 100 weights approximately10,000 pounds and runs on twenty driven wheels expanding toapproximately 24 inches in diameter at 2200 rpm (i.e., a landing speedof 157 mph). In this variation, the drivetrain 120 includes twentybrushless DC motors, each producing approximately 500 horsepower at 2000rpm and connected directly to one drive wheel; the motors can thusproduct a total of 10,000 horsepower, which may be sufficient toaccelerate the tram 100 (unloaded) to a landing speed of an aircraft(e.g., ˜157 mph) within one quarter of a mile (e.g., within ˜7.8seconds) at ˜40% power. In this variation, the drivetrain 120 can sourcepower from a DC or AC power rail extending along the runway, asdescribed below. The tram 100 can also operate the motors in a generatormode to convert kinetic energy into electrical energy and feed thiselectrical energy back into the power rail to decelerate the tram 100(and the aircraft during a landing routine).

Alternatively, the drivetrain 120 can include a gasoline, diesel, orturbine engine producting 12,000 horsepower and distributing power toits drive wheels through a gearbox exhibiting approximately 20% powerloss in order to achieve similar acceleration and speed metrics. Yetalternatively, the drivetrain 120 can run on free wheels and include ajet or rocket engine configured to accelerate the tram 100. However, thedrivetrain 120 can include any other one or more motors, engines, orother motive systems to accelerate the tram 100.

The drivetrain 120 can also include friction brakes, such as frictiondisk or drum brakes on each wheel. Alternatively, the drivetrain 120 caninclude electromechanical disk Eddy current brakes on its wheels. Thedrivetrain 120 that includes a jet or rocket engine can also include areverse thruster, and the tram 100 can actuate the reverse thruster toslow the tram 100 and the aircraft during a landing routine or to slowthe tram 100 following a takeoff routine. The drivetrain 120 thatengages a location and/or power rail—as described below—can also includean electromagnetic element mounted to a rail follower 122 that runsalong or adjacent the location and/or power rail; the tram 100 can powerthe electromagnetic element to induce Eddy currents in the rail, therebyslowing the tram 100, as described below.

4.2 Grid Power

In the variation described above in which the drivetrain 120 includes aset of electric motors, the drivetrain 120 can be configured tointerface with an electrified power rail running the length of therunway, such as buried under the runway, extending above and to one sideof the runway, or extending above ground and centered along the runway.In this variation, the tram 100 can include a rail follower 122extending from the chassis 100, configured to engage the power rail, andconfigured to source electrical power from the power rail, as shown inFIGS. 1A and 1B. The drivetrain 120 can thus source power from the powerrail via the rail follower 122 to power the set of electric motorsduring takeoff and landing routines.

In this variation, the power rail can extend from the runway to eachgate in the airport, and the tram 100 can source power from the powerrail via the rail follower 122 to power the electric motors as the tram100 taxis an aircraft between the runway and assigned gates betweenlanding and takeoff routines. Alternatively, the power rail can extendalong the runway only, and the rail follower 122 can transiently engagethe power rail proximal the front end of the runway and disengage therail follower 122 proximal the terminus of the runway. In thisimplementation, the tram 100 can also include backup electric batteriesor a backup generator to supply energy to the motors to transport theaircraft from the terminus of the runway to its assigned gate followinga landing routine and then from its assigned gate back to the head ofthe runway in preparation for subsequent takeoff routine. The tram 100can additionally or alternatively include a power coupling adjacent thelatch 130 and configured to engage a power receptacle on the undersideof the fuselage of the aircraft; in this implementation, the tram 100(e.g., the controller 160) can trigger the rail follower 122 to retractfrom or disengage the power rail upon conclusion of a landing routine,and the drivetrain 120 can source power from the aircraft via the powercoupling—during navigation from the terminus of the runway to anassigned gate in the airport and later back to the head of the runwayfor a subsequent takeoff routine—following retraction of the railfollower 122 from the power rail. For example, once the tram 100 engagesand latches onto the aircraft, the aircraft can deactivate its primaryengines, maintain its auxiliary engine as active, and supply sufficientpower to the drivetrain 120 via the power coupling to navigate the tram100 and the aircraft to an assigned gate.

In this variation, the drivetrain 120 can also operate the electricmotors in a generator mode to transform kinetic energy into electricalenergy and then feed this electrical energy back into the power rail(and therefore back into the “grid”) via the rail follower 122, therebyrecovering energy while slowing the tram 100 following a takeoff routineor slowing the tram 100 and the aircraft during a landing routine. Forexample, once the latch 130 on the tram 100 engages a correspondinglatch receiver on the aircraft during a landing routine, as describedbelow, the controller 160 can trigger the drivetrain 120 to transitionthe electric motors into the generator mode to feed energy back into thepower rail via the rail follower 122 in order to actively decelerate thechassis 100 and the aircraft.

In the variation described above in which the rail follower 122 includesan electromagnetic element configured to run along the power rail, thedrivetrain 120 can additionally or alternatively supply power to theelectromagnetic element to induce Eddy currents in the power rail,thereby slowing the tram 100. For example, the drivetrain 120 cantransition the electric motors into the generator mode to feedelectrical energy to the electromagnetic element on the rail follower122 to induce Eddy currents in the power rail to slow the chassis 100and the aircraft following engagement of the latch 130 during thelanding routine; the tram 100 can also feed excess electrical energy notneeded to energize the electromagnetic element back into the power railin order to recuperate this energy, as described above. The tram 100 canadditionally or alternatively include a rail follower 122 thatinterfaces with a location rail, as described below; the drivetrain 120can implement similar methods and techniques to brake the tram 100against the location rail by supplying power to an electromagneticelement in the rail follower 122 to induce Eddy currents in the locationrail.

The rail follower 122 can also be mounted to a suspension systemconfigured to absorb variations in distance of the power rail below (oradjacent) the tram 100 along the length of the runway. Furthermore, forthe power rail that defines an undercut feature, the rail follower 122can engage the undercut features, and the tram 100 can passively oractively tension the rail follower 122 against the power rail tovertically retain the tram 100 over the power rail, such as to brace thetram 100 against lifting off of the runway (or off of the rail) as theaircraft ascends during a takeoff routine.

However, the tram 100 can source and supply power from and to the powerrail in any other way. The tram 100 can also include multiple railfollowers, such as a front rail follower proximal a front of the tram100 and a rear rail follower proximal a rear of the tram 100.

4.3 Lateral Location

In one variation as shown in FIG. 1B, the drivetrain 120 is configuredto interface with a location rail, such as distinct from or physicallycoextensive with the power rail described above, configured to laterallylocate the tram 100 along the length of the runway. In particular, thelocation rail can be configured to retain the lateral position of thetram 100—such as against lateral loads due to crosswinds—as the tram 100moves along the length of the runway during takeoff and landingroutines. For example, the location rail can be integrated into therunway or can be elevated above a ground surface to define a linearelevated runway. For example, the location rail can define a monorail,or the runway can include a pair of parallel and offset location rails.

The drivetrain 120 can include one or a set of rail followers configuredto engage the location rail(s), and the location rail(s) can resistlateral movement of the tram 100 (e.g., “drift”) relative to thelongitudinal axis of the runway via the rail follower(s). Wheels in thedrivetrain 120 can also act directly on the location rail(s) toaccelerate the tram 100 forward.

In this variation, like the power rail, the location rail can define anundercut, and the rail follower 122 on the tram 100 can extend over andengage the undercut to vertically retain the tram 100 to the locationrail during takeoff and landing routines, as shown in FIG. 1B. Forexample, the rail follower 122 can include a free wheel configured toengage the undercut on the location rail, and the tram 100 can preloadthe rail follower 122 in tension against the location rail.

However, the drivetrain 120 can interface with one or more power and/orlocation rails in any other way to source power, to sink power, tolocate the tram 100 laterally along a runway, and to locate the tram 100vertically along the runway.

5. Aircraft Engagement Mechanisms

As shown in FIGS. 1B, 2A, and 2B, the latch 130 is coupled to thechassis 100 and is configured to selectively engage a latch receivermounted to an underside of a fuselage of an aircraft; and an alignmentfeature 132 is arranged adjacent the latch 130, is configured toselectively engage an alignment receiver mounted to the underside of thefuselage of the aircraft, and is configured to communicate forcesparallel to an anteroposterior axis of the chassis 100 into theaircraft. Generally, the latch 130 and the alignment feature 132cooperate to transiently engage like features on the aircraft (e.g., onthe fuselage and/or on the wings of the aircraft): to “catch” anddecelerate the aircraft during a landing routine; and to accelerate andthen release the aircraft during a takeoff routine.

In particular, the tram 100 includes one or more alignment features,such as in the form of alignment pins, configured to make first contactwith like features on a fuselage of an aircraft and prior to actuationof the latch 130 during the landing routine. Once the alignmentfeature(s) meets and is inserted into or receives an alignment receiveron the aircraft during a landing routine, the controller 160 can triggerthe latch 130 to engage the latch receiver on the aircraft, therebyretaining the aircraft against the tram 100. The tram 100 can thendecelerate, and the alignment feature(s) and the latch 130 cancommunicate force into the aircraft longitudinally to decelerate theaircraft to a taxiing speed. Similarly, during a takeoff routine, thealignment feature(s) and the latch 130 can communicate force into theaircraft longitudinally to accelerate the aircraft to a takeoff speed.Therefore, the alignment feature(s) and the latch 130 can cooperate tocommunicate fore and aft forces from the tram 100 into the aircraft whenthe tram 100 accelerates (i.e., during takeoff routines) and brakes(i.e., during landing routines), respectively.

The tram 100 can also include a cradle 140 configured to support an areaof the underside of the aircraft, such as during a takeoff cycle untilthe aircraft creates sufficient lift to ascend off of the tram 100 andduring a landing cycle once the aircraft has slowed sufficiently todescend into full contact with the tram 100. Together, the latch 130,the alignment feature 132, and the cradle 140 can define a “dock” on thetram 100.

5.1 Aircraft Receiver

As shown in FIG. 2B, the aircraft can be manufactured or retrofit withan aircraft receiver system defining: a latch receiver configured toengage the latch 130 and integrated into a structural region of theaircraft, such as along the underside of the fuselage between theprimary wings of the aircraft, an alignment receiver configured toreceive the alignment feature 132 on the tram 100; and cradle points142, such as including hard points (e.g., structural load surfaces),arranged across the underside of the fuselage and/or wings of theaircraft, such as one cradle point 142 under each of the left and rightprimary wings, the nose, and the tail of the aircraft.

The aircraft can also be manufactured or retrofit with multiple aircraftreceiver systems, each configured to interface with one dock on the tram100.

5.2 Alignment Feature and Latch

In one implementation shown in FIG. 3 , an alignment receiver on theaircraft includes a tapered bore extending into the fuselage of theaircraft; and the alignment feature 132 includes a tapered (e.g.,conical, frustoconical) alignment pin extending upwardly from the tram100 and defining an external taper matched to the alignment receiver onthe aircraft. Thus, as the aircraft descends toward the tram 100 and/oras the tram 100 raises the dock toward the aircraft during a landingroutine, the alignment pin can self-center on its correspondingalignment receiver in the aircraft. In this implementation, the latch130 can define an overcam latch including an electromechanical actuatorconfigured to rotate the latch 130 forward (e.g., from a recessedposition below the dock) into contact with the latch receiver on theaircraft. Once the alignment pin is sufficiently inserted into itsalignment receiver, the tram 100 (e.g., the controller 160) can triggerthe electromechanical actuator to advance the latch forward past itsovercam position, which can draw the latch 130 into contact with thelatch receiver on the aircraft and then downward toward the dock,thereby drawing the fuselage into the dock (or raising the dock towardthe aircraft) and locking the latch 130 against the latch receiver inthis overcam position.

In another implementation shown in FIGS. 2A and 2B, the latch 130 andthe alignment feature 132 are physically coextensive. In one example,the alignment feature 132 defines an external frustoconical section anda set of bores extending (substantially) perpendicular to the axis ofthe frustoconical section. The latch 130 can include a set of bearingsarranged in and captured by bores in the alignment feature 132; and anexpansion driver running inside the alignment feature 132 and defining ashoulder configured to drive the set of ball bearings outwardly in theirbores in an advanced position and configured to release the ballbearings back into the bores in a retracted position. In thisimplementation, the alignment receiver can define an internalfrustoconical section and an internal shoulder. During a landingroutine, the tram 100 (e.g., the controller 160) can trigger a latch 130actuator to transition the expansion driver from the retracted positioninto the advanced position to lock the set of ball bearings against theshoulder in the alignment receiver in response to insertion of athreshold length of the alignment feature 132 on the tram 100 into thealignment receiver on the aircraft (e.g., in response to descent of thealignment receiver onto the alignment feature 132) during a landingroutine, thereby retaining the aircraft against the tram 100 prior totriggering the drivetrain 120 to actively brake the tram 100 and theaircraft. Similarly, the controller 160 can trigger the latch 130actuator to transition the expansion from the advanced position into theretracted position to release the set of ball bearings and to permit theset of ball bearings to retract from the shoulder in the alignmentreceiver, thereby releasing the alignment receiver from the alignmentfeature 132 and releasing the aircraft from the tram 100, in response toacceleration of the chassis 100 and the aircraft to a takeoff speedspecified for the aircraft and/or in response to detecting a thresholdtension on the alignment feature 132, which may indicate achievement ofa target lift on the aircraft during a takeoff routine. Therefore, inthis implementation, the latch 130 and alignment feature 132 can definean integrated quick-release mechanism for transiently engaging, aligningwith, and locking against an aircraft receiver system arranged on anaircraft.

The tram 100 can also include multiple discrete or integrated latches(the first latch 130, a second latch 130B, and a third latch 130C)and/or alignment features (e.g., the first alignment feature 132, asecond alignment feature 132B, and a third alignment feature 132C). Forexample, the tram 100 can include four alignment features arranged in adiamond pattern, including an alignment feature 132 proximal each of thenose, left wing-to-fuselage junction, right wing-to-fuselage junction,and the tail of the aircraft to transiently support the aircraft in sixdegrees of freedom once engaged to alignment receivers in like locationson the aircraft. In this example, the tram 100 can include a similararrangement of latches adjacent or integrated into these four alignmentfeatures. However, the latch 130 and the alignment feature 132 in thetram 100 can define any other common or separate structure, and the tram100 can include any other number or arrangement of latches and alignmentfeatures. The aircraft receiver system can similarly include any othernumber and arrangement of latch receivers and the alignment receiversdefining common or separate structures configured to mate withcorresponding latches and alignment features on the tram 100.

5.4 Cradle

As described above and shown in FIGS. 1A and 3 , the tram 100 caninclude a cradle 140 configured to support the aircraft duringacceleration and deceleration along a runway, such as against rotationin pitch, yaw, and roll during takeoff and landing routines. Forexample, the cradle 140 can define a scalloped bed extending along thetop of the tram 100 parallel to the anteroposterior axis of the tram 100and configured to receive the fuselage and/or wings of an aircraft. Inthis example, the scalloped bed can define a generic geometry configuredto accept a standard fuselage geometry or can define a geometry matchedto a size, class, make, or model of aircraft.

The cradle 140 can additionally or alternatively include a set of cradlepoints 142 configured to contact and support corresponding hard pointsdefined across the underside of the fuselage and/or wings of theaircraft, as shown in FIGS. 1A, 1B, and 3. In one implementation, thecradle points 142 can be fixedly coupled to the tram 100 in a genericcradle 140 pattern and at generic heights such that the cradle points142 mate with hard points arranged in a generic three-dimensionalpattern in a variety of aircraft of different sizes, classes, makes, ormodels.

In the foregoing implementation, the cradle points 142 can also beadjustable. For example, the cradle 140 can include a set of (e.g.,four) cradle points 142, each mounted to a retractable pin coupled tothe chassis 100 to define an adjustable support pin configured to extendand retract to a target location to meet a corresponding hard point onthe fuselage of an aircraft—caught by the tram 100 during a landingroutine—based on known vertical positions of hard points on aircraft ofthis type. In particular, during a landing routine, the controller 160can access a database of vertical positions of hard points arrangedacross the aircraft and extend the set of retractable pins according tothe database of vertical positions in order to engage each cradle point142 with its corresponding hard point on the aircraft.

In the foregoing example, the tram 100 (e.g., the controller 160) canalso extend the adjustable pins to meet corresponding hard points on theaircraft once the latch 130 engages the latch receiver on the aircraftand before triggering the drivetrain 120 to decelerate in order tosupport the aircraft, particularly against pitching forward. The tram100 can also actively support the aircraft and (slowly) retract theadjustable pins and the latch 130 down into the scalloped bed as theaircraft decelerates and creates reduced total lift. Therefore, thecradle 140 can include a set of cradle points 142 of adjustable heightto accommodate multiple unique types of aircraft of different geometriesand containing cradle feature points 142 in the same plan orientationbut at different heights across the aircraft, as shown in FIGS. 1A, 1B,and 3 .

In a similar implementation, the cradle 140 includes multiple adjustablecradle points 142 distributed across the top of the tram 100, and thetram 100 selectively extends a subset of these adjustable cradle points142 to meet corresponding hard points on an aircraft based on a type ofthe aircraft as the aircraft descends onto the tram 100 during a landingroutine. For example, the cradle 140 can include: a first set of fouradjustable cradle points 142 distributed according to a unique cradle140 pattern for small aircraft; a second set of four adjustable cradlepoints 142 distributed according to a unique cradle 140 pattern formedium-sized aircraft; and a third set of four adjustable cradle points142 distributed according to a unique cradle 140 pattern for largeaircraft. In this example, as the tram 100 retracts an aircraft downwardinto the cradle 140 during a landing routine, the tram 100 can extendone of these sets of adjustable cradle points 142 to preset heights tomeet corresponding hard points on the aircraft based on the known typeand size of the aircraft, such as described above.

In the foregoing implementation, each hard point on the aircraft candefine an extended hard surface, such as a substantially planar200-millimeter-square surface. Each cradle point 142 can be tipped witha bearing or caster configured to run across a corresponding hardsurface on the aircraft to provide continuous vertical support to theaircraft during takeoff and landing routines, such as while the aircraftrotates about the dorsoventral axis of the tram 100 into alignment withthe anteroposterior axis of the tram 100 while slowing in the presenceof a crosswind during a landing routine or as the aircraft rotates aboutthe dorsoventral axis of the tram 100 out of alignment with theanteroposterior axis of the tram 100 while accelerating in the presenceof a crosswind during a takeoff routine.

5.5 Motion Platform: Degrees of Freedom

In one variation shown in FIGS. 1B and 2A, the dock (e.g., the latch 130and the alignment feature 132) are integrated into a motion platform 134that enables active or passive adjustment of the orientation of thelatch 130 and the alignment features relative to the chassis 100 duringtakeoff and landing routines.

In one implementation, the motion platform 134 includes a gimbalarranged over the cradle 140 on the top of the tram 100 and exhibitingadjustable pitch, yaw, and roll axes. In this implementation, the dockcan be arranged on the gimbal (i.e., coupled to the chassis 100 via thegimbal). The tram 100 can also include a set of gimbal actuators coupledto each gimbal axis and configured to actively adjust angular positionsof the pitch, yaw, and/or roll axes of the gimbal to actively align thealignment feature 132 to it corresponding alignment receiver in thefuselage as the aircraft approaches the tram 100 during a landingroutine. In particular, the tram 100 (e.g., the controller 160) canactively adjust the pitch, yaw, roll, vertical and/or lateral positionsof the gimbal on the chassis 100 to align the alignment feature 132 withthe corresponding alignment receiver on the chassis 100 based on opticaldata collected by the optical sensor 150 during a landing routine, asdescribed below; the tram 100 can also unlock axes of the gimbal duringa takeoff routines and once the latch 130 has engaged the latch receiverduring a landing routine

(Alternatively, the gimbal can include free (i.e., controlled) axes; thealignment feature 132 can include an electromagnetic element; and thecorresponding alignment receiver in the aircraft can include a ferrousor magnetic element. In this implementation, as the aircraft approachesand lowers over the tram 100 during a landing routine, the tram 100 canactuate the electromagnetic element in the alignment feature 132, whichthen magnetically couples to the ferrous element in the correspondingalignment receiver to draw the alignment feature 132 toward and intocontact with the alignment receiver on the fuselage of the aircraft,thereby also drawing the gimbal toward the aircraft and aligning thelatch 130 with its corresponding latch receiver on the aircraft.)

In the variation described above in which the tram 100 interfaces with alocation rail in the runway for lateral location of the tram 100 duringtakeoff and landing routines, the tram 100 also include a lateraladjustment subsystem 135 configured to move the motion platform 134—andtherefore the dock—laterally relative to the tram 100 in order tolaterally align the alignment feature 132 to the alignment receiver onthe aircraft, as shown in FIG. 2A. In particular, because the lateralposition of the chassis 100 may be controlled (e.g., substantiallyfixed) by the rail extending along the runway, the motion platform 134can include a lateral adjustment subsystem 135—mounted between thechassis 100 and the dock—in order to accommodate lateral misalignment ofthe aircraft to the tram 100 during a landing routine. As describedbelow, the tram 100 can track the position of the aircraft aboverelative to the tram 100—such as based on optical fiducials detected inoptical images recorded by the optical sensor 150 once the aircraftdescends to within a threshold distance above the tram 100—and canactively drive the motion platform 134 to a lateral position that alignsthe alignment feature 132 to the corresponding alignment receiver on theaircraft above during a landing routine.

5.6 Telescoping Boom

In another variation shown in FIGS. 1B and 2A, the tram 100 includes atelescoping boom 136 that supports the dock—via the motion platform134—on the chassis 100 and that can be actively raised and loweredrelative to the chassis 100, such as to recess the dock below the cradle140 (e.g., after releasing the aircraft during a takeoff routine) and toextend the dock up to one meter above the cradle 140 (e.g., just beforeengaging the aircraft during a landing routine). For example, thetelescoping boom 136 can include a hydraulic ram capable of lifting andretracting 500 tons (e.g., the weight of a fully-laden large passengeraircraft) over one meter above the chassis 100.

During a landing routine, the tram 100 (e.g., the controller 160) canactively control a boom actuator (e.g., a hydraulic pump and valvesystem) to extend the telescoping boom 136, thereby raising the dockabove the chassis 100 to meet the aircraft, as shown in FIG. 4 . Oncethe latch 130 and alignment feature 132 have engaged and latched to thefuselage, the tram 100 can actively retract the telescoping boom 136 todraw the aircraft into the cradle 140, such as for the tram 100 that isvertically located and retained by a rail extending along the runway, asdescribed above. Alternatively, once the latch 130 and alignment feature132 have engaged and latched to the fuselage, the tram 100 can open arelief valve on the hydraulic pump to release the telescoping boom 136to move vertically with the aircraft as the aircraft descends, therebylimiting transmission of lift from the aircraft into the tram 100, whichmay otherwise reduce braking force of the drivetrain 120 and/or upsetairflow under the tram 100 as the tram 100 is lifted from the runway.Therefore: the telescoping boom 136 can couple the dock to the chassis100 and can be configured to raise the latch 130 and the dock above thechassis 100 to meet the aircraft during the landing routine; and thecontroller 160 can extend the telescoping boom 136 upward to mate thealignment feature 132 to the alignment receiver on the aircraft. Oncethe latch engages the latch features, the controller can retract thetelescoping boom 136 to draw the aircraft into the cradle 140 and tomate the set of cradle points 142 in the cradle 140 to hard pointsdefined across the aircraft in response to engagement of the latch 130with the latch receiver.

Similarly, during a takeoff routine, the tram 100 can unlock thetelescoping boom 136, thereby permitting the telescoping boom 136 tofreely extend while the tram 100 continues to communicate force into theaircraft in the forward direction, as shown in FIG. 5 . In particular asthe speed of the tram 100 and aircraft increases, the aircraft's wingscreate greater lift, which causes the aircraft to ascend off of thecradle 140 and extends the telescoping boom 136. By unlocking thetelescoping boom 136, the tram 100 can thus decouple ascension of theaircraft from motion of the tram 100. Once the telescoping boom 136reaches a target extended length (or a threshold height above thechassis 100), the controller 160 can trigger the latch 130 to releasethe latch receiver. Once the latch 130 releases the latch receiver, thetram 100 can rapidly retract the telescoping boom 136—such as to bringthe dock flush or below the cradle 140—in order to prevent impactbetween the aircraft and the dock once the aircraft and the dockseparate. For example, the tram 100 can (rapidly) retract thetelescoping boom 136 once the latch 130 is released in order to preventdamage to the fuselage of the aircraft in the event of a slight drop inthe aircraft's altitude during takeoff, such as due to a wind gust. Oncethe aircraft has reached a predefined altitude above the tram 100 (e.g.,two meters), the tram 100 can decelerate and autonomously return to thehead of the runway to execute a landing routine with another aircraft.

In this variation, the tram 100 can similarly extend cradle points 142in the cradle 140 to maintain contact with the hard points on theaircraft as the telescoping boom 136 rises during a takeoff routine. Forexample, the tram 100: can measure load or force on each cradle point142 via load cells or other sensors in the cradle 140 throughout thetakeoff routine (e.g., at a sampling rate of 10 Hz); and can activelyadjust the vertical position of each cradle point 142 to achieve asubstantially uniform load across all cradle points 142 in contact withthe aircraft—such as up to a threshold roll angle of the aircraft and/orwithin predefined pitch angle limits for the aircraft (e.g., to preventthe aircraft's tail from containing the runway during ascent)—therebyachieving substantially uniform support across hard points on theaircraft as the aircraft accelerates, pitches back, and ascends duringthe takeoff routine.

Furthermore, in this variation, the tram 100 can adjust output of theboom actuator to actively damp the telescoping boom 136. For example,during a takeoff routine, the tram 100 can actively adjust a pressurebehind the telescoping boom 136 (e.g., by controlling pressure output ofthe boom actuator) in order to actively damp forces communicateddownward into the telescoping boom 136 by the aircraft, therebysoftening rapid drops in altitude of the aircraft (e.g., due to localwind gusts). However, in this example, the tram 100 can permit(substantially) free motion of the telescoping boom 136 in the upwarddirection in order to prevent the aircraft from lifting the tram 100 offof the runway as it ascends.

During a takeoff routine, the tram 100 can also preload the telescopingboom 136 (and the adjustable cradle points 142) in extension in order toactively promote ascension of the aircraft off of the tram 100. Forexample, for an aircraft with an average or common takeoff weight ofapproximately 350 tons, the tram 100 can power the boom actuator topreload the telescoping boom 136 with 50 tons of lift.

However, the tram 100 can include a telescoping boom 136 of any otherform and actuated in any other way. The tram 100 can similarly include asingle- or multi-jointed arm similarly configured: to elevate the dockinto alignment with the fuselage of the aircraft; to lower into thecradle 140 as the aircraft descends during a landing routine; and torise with the aircraft as the aircraft ascends during a takeoff routine.

5.7 Tram Load

The tram 100 can also measure a laden weight of the aircraft once loadedinto the cradle 140 and prior to initiating a takeoff routine. Forexample, in the variation described above in which the tram 100 includesa telescoping boom 136 actuated by a hydraulic pump and valve system,the controller 160 can record a pressure in the hydraulic system—via apressure sensor coupled to a supply or return line—necessary to carrythe aircraft while the tram 100 is static, and the controller 160 canconvert this pressure into a weight of the aircraft based on across-sectional area of the telescoping boom 136. Alternatively, thetram 100: can include a pressure sensor or strain gauge integrated intoor arranged under the dock, and the controller 160 can sample thepressure sensor or strain gauge to determine the laden weight of theaircraft. The controller 160 can then set various takeoffparameters—such as preload on the telescoping arm and acceleration rateof the drivetrain 120—based on the laden weight of the aircraft.

6. Controller and Sensors

As shown in FIGS. 1A and 1B, the tram 100 includes a controller 160configured to sample various sensors and to control various actuators inthe tram 100 while in operation in order to autonomously executelanding, taxiing, and takeoff routines, as described below.

As shown in FIGS. 1A, 1B, and 2A, the tram 100 further includes anoptical sensor 150 that faces upwardly from the chassis 100 and isconfigured to output a sequence of optical images. For example, theoptical sensor 150 can include: a color (e.g., RGB) camera; a colorcamera with a color filter (e.g., a filter in the red, blue, or greencolor spectrums); or an infrared camera mounted to the motion platform134 or to the dock adjacent the alignment feature 132.

During a landing routine, the controller 160 can: sample the opticalsensor 150 regularly, such as at a rate of 15 Hz; implement computervision techniques to detect, identify, and track the position of anoptical fiducial—arranged on the aircraft—in the field of view of theoptical sensor 150; adjust a speed (e.g., a power output) of thedrivetrain 120 in order to maintain longitudinal alignment between thealignment feature 132 on the tram 100 and the alignment receiver on theaircraft based on positions of the optical fiducial in the field of viewof the optical sensor 150; and adjust the position of the motionplatform 134 and/or telescoping boom 136 in order to maintain pitch,yaw, roll, and lateral alignment between the alignment feature 132 onthe tram 100 and the alignment receiver on the aircraft similarly basedon positions of the optical fiducial in the field of view of the opticalsensor 150, as shown in FIG. 4 .

In one implementation, the aircraft includes an active optical fiducialon its fuselage, such as in the form of a lamp or cluster of lampsoutputting light at a particular wavelength (e.g., in the visible orinfrared spectrums) and/or blinking at a particular frequency, as shownin FIG. 1B. In this implementation, the optical sensor 150 can include afilter that passes light within a narrow spectrum containing the outputwavelength of the active optical fiducial; and the controller 160 candetect and identify the optical fiducial in the field of view of theoptical sensor 150 based on presence of a bright region in an opticalimage recorded by the optical sensor 150. Alternatively, the opticalsensor 150 can output a sequence (e.g., a video stream) of unfilteredoptical images, and the controller 160 can detect and identify theoptical fiducial based on a color, intensity, pattern, and/or flutterrate of the groups of pixels in these optical images.

Once the controller 160 detects and identifies the optical fiducial onthe aircraft in a field of view of the optical sensor 150 (i.e.,substantially in real-time), the controller 160 can implement objecttracking techniques to track the optical fiducial over time. Thecontroller 160 can also implement known intrinsic and/or extrinsicparameters of the optical sensor 150, such as a known orientation andposition of the field of view of the optical sensor 150 relative to thealignment feature 132 and distortion of the optical sensor 150, tocalculate a location of a target pixel in an optical image that, whencoincident the centroid of the optical fiducial represented in theoptical image, indicates that the alignment feature 132 is aligned intranslation to the corresponding alignment receiver in the aircraft, asshown in FIG. 4 . Once the controller 160 identifies the opticalfiducial in an optical image, the controller 160 can calculate acentroid of the optical fiducial and calculate a lateral offset and alongitudinal offset of the centroid from the target pixel. Thecontroller 160 can then trigger the drivetrain 120 to accelerate ordecelerate based on whether the centroid of the optical fiducial isahead of or behind the target pixel; similarly, the controller 160 cantrigger the motion platform 134 to shift left or shift right based onwhether the centroid of the optical fiducial is to the right or to theleft of the target pixel. The controller 160 can repeat this process foreach optical image received from the optical sensor 150. Therefore, thecontroller 160 can interface with an actuator in the tram 100 to adjusta lateral position of the motion platform 134 described above to alignthe alignment feature 132 with its corresponding alignment receiver onthe aircraft by maintaining the first optical fiducial proximal a firsttarget position in the first sequence of optical images as the aircraftapproaches the runway during the landing routine, as shown in FIG. 4 .

The aircraft can include multiple distinct optical fiducials or apattern of optical fiducials, such as outputting different wavelengths(e.g., colors) of light and/or blinking at different rates. Thecontroller 160 can thus implement the foregoing methods and techniquesto: detect and track each optical fiducial in an optical image receivedfrom the optical sensor 150; calculate target locations for each opticalfiducial in these optical images to align the alignment feature 132 toit corresponding alignment receiver; and then adjust the position of themotion platform 134 on the tram 100 according to deviation of the actuallocations of the optical fiducials from their target locations. In thisimplementation, the controller 160 can also calculate a distance of theaircraft from the dock based on distances between optical fiducialsrepresented in these optical images—such as based on a known geometryand dimensions of the optical fiducial pattern on the aircraft—and thenextend the telescoping boom 136 upward to reduce this distance as theaircraft descends toward the tram 100. For example, the controller 160can calculate offset distances from the alignment feature 132 to thealignment receiver on the aircraft based on distances between a firstoptical fiducial and a second optical fiducial detected in the firstsequence of optical images; once such an offset distance from thealignment feature 132 to the alignment receiver on the aircraft dropsbelow a threshold distance, the controller 160 can transition: fromimplementing closed-loop controls to adjust speed of the drivetrain 120to sequentially arrive at tram waypoints in a predefined sequence oftram waypoints concurrent with receipt of confirmations of arrival ofthe aircraft at corresponding aircraft waypoints in a predefinedsequence of aircraft waypoints, as described below; to implementingclosed-loop controls to adjust speed of the drivetrain 120 and aposition of the alignment feature 132 relative to the chassis 100 basedon positions of the optical fiducials detected in optical imagesrecorded by the optical sensor 150, as shown in FIG. 4 .

Similarly, the controller 160 can: calculate an angular offset of theaircraft relative to the alignment feature 132 about pitch, yaw, and/orroll axes based on relative sizes and positions of the optical fiducialsdetected in the optical images and based on a known geometry anddimensions of the optical fiducial pattern on the aircraft; and thenadjust the pitch, yaw, and/or roll position of the motion platform 134to reduce these angular offsets. The controller 160 can repeat thisprocess for each optical image received from the optical sensor 150 oncethe aircraft reaches a threshold distance from the tram 100.

Furthermore, the tram 100 can include multiple optical sensors, such asone optical sensor 150 adjacent each of multiple alignment features onthe dock, as shown in FIG. 2A, and the controller 160 can fuse positionsof optical fiducials detected in groups of optical images recorded bythe set of optical sensors to adjust the position of the dock and/or thespeed of the tram 100 in real-time. For example, the tram 100 caninclude: a first alignment feature 132 arranged on the motion platform134; a second alignment feature 132 arranged on the motion platform 134and offset from the first alignment feature 132; a third alignmentfeature 132 arranged on the motion platform 134 and offset from thefirst alignment feature 132 and the second alignment feature 132; afirst optical sensor 150 arranged at a first location on the motionplatform 134 adjacent a first alignment feature 132; a second opticalsensor 150B arranged on the motion platform 134 adjacent the secondalignment feature 132; and a third optical sensor 150C arranged on themotion platform 134 adjacent the third alignment feature 132. In thisexample, the controller 160 adjusts a speed controller 160 and a brakingsystem in the drivetrain 120 and adjusts a position of the motionplatform 134 relative to the chassis 100 to: maintain a first opticalfiducial (e.g., emitting infrared light at a first wavelength) on theaircraft proximal a first target position in a first field of view ofthe first optical sensor 150, maintain a second optical fiducial (e.g.,emitting infrared light at a second wavelength) on the aircraft proximala second target position in a second field of view of the second opticalsensor 150B, and maintain a third optical fiducial (e.g., emittinginfrared light at a third wavelength) on the aircraft proximal a thirdtarget position in a third field of view of the third optical sensor150B, such as from a time that the aircraft is within a thresholddistance of the tram 100 until the first alignment feature 132 engages afirst alignment receiver in the aircraft, the second alignment feature132 engages a second alignment receiver in the aircraft, and the thirdalignment feature 132 engages a third alignment receiver in theaircraft. Therefore, in this implementation: the aircraft can includeoptical fiducials adjacent alignment receivers; the tram 100 can includean optical sensor 150 adjacent each alignment feature 132; and thecontroller 160 can implement closed-loop controls to adjust the speed ofthe aircraft and the position of the motion platform 134 during alanding routine to maintain the position of these optical fiducials intarget positions in the fields of view of corresponding optical sensorsuntil the alignment features meet and engage corresponding alignmentreceivers in the aircraft, as which time the controller 160 can triggerthe latch 130 to engage the latch receiver on the aircraft.

As described above, the tram 100 can also include multiple docks, suchas arranged on independently-actuated motion platforms (e.g., gimbals),as shown in FIG. 3 . In this implementation, the controller 160 canimplement the foregoing methods and techniques to independently aligneach alignment feature on each dock with its corresponding alignmentreceiver on the aircraft. For example, the tram 100 can include: a frontgimbal arranged proximal a front of the chassis 100; a latch 130arranged on the front gimbal and configured to selectively engage afront latch receiver arranged proximal a front of the fuselage of theaircraft; a first alignment feature 132 arranged on the front gimbaladjacent the front latch and configured to selectively engage a frontalignment receiver arranged proximal the front of the fuselage of theaircraft; a rear gimbal arranged proximal a rear of the chassis 100; arear latch arranged on the rear gimbal and configured to selectivelyengage a rear latch receiver arranged proximal a rear of the fuselage ofthe aircraft; and a rear alignment feature 132 arranged on the reargimbal adjacent the rear latch, configured to selectively engage a rearalignment receiver arranged proximal the rear of the fuselage of theaircraft, and configured to cooperate with the front alignment feature132 to communicate forces parallel to the anteroposterior axis of thechassis 100 into the aircraft. In this example, the controller 160 canindependently adjust lateral positions of the front gimbal and the reargimbal to accommodate a yaw angle of the aircraft, such as in thepresence of a headwind during approach of the aircraft toward therunway, by aligning the first alignment feature 132 with the firstalignment receiver on the aircraft and aligning the rear alignmentfeature 132 with the rear alignment receiver on the aircraft, such asaccording to positions of optical fiducials detected in optical imagesrecorded by distinct optical sensors arranged on the front and reargimbals as described above.

7. Communications

The tram 100 can also include a wireless communication module 152configured to communicate over (medium- or long-range) wirelesscommunication protocol with a remote computer system, such as with aremote control tower over the Internet to receive a sequence of tramwaypoints and/or triggers to execute a takeoff or landing routine, asdescribed below. The wireless communication module 152 can additionallyor alternatively communicate with aircraft over (short-range) wirelesscommunication protocol, such as to receive confirmation of a systemcheck at the aircraft prior to executing a takeoff routine, as describedbelow.

Furthermore, the tram 100 can include a geospatial location sensor 154configured to interface with an external geospatial network to track ageospatial location and/or orientation of the tram 100 such as at a rateof 10 Hz during execution of a landing routine. The tram 100 can returnits geospatial locations and/or orientations to the aircraft and/or tothe remote computer system via the wireless communication module 152,such as to enable the remote computer system to update tram waypointsfor the tram 100 in real-time based on the geospatial location of thetram 100 relative to the geospatial location of the aircraft, asdescribed below.

8. Landing Routine

In one variation shown in FIG. 4 , the tram 100 interfaces with theremote computer system (e.g., the control tower) to execute a landingroutine method S100, including, at the remote computer system: assigninga sequence of aircraft waypoints—to an aircraft—along a landing approachpath and along a runway at an airport in Block S110; assigning asequence of tram waypoints—to a tram—along the runway in Block S112;prompting the tram 100 to navigate to a first tram waypoint, in thesequence of tram waypoints, at a head of a runway in preparation for alanding routine in Block S120; and, in response to the aircraft reachinga trigger waypoint, in the sequence of aircraft waypoints, preceding therunway, triggering the tram 100 to accelerate to a landing speed of theaircraft in Block S122. The landing routine can also include, at thetram 100: adjusting output power of a drivetrain in the tram 100 tosequentially arrive at each tram waypoint in the sequence of tramwaypoints concurrent with arrival of the aircraft at correspondingaircraft waypoints in the sequence of aircraft waypoints in Block S130;recording a sequence of optical images through an optical sensor 150arranged on the tram 100 in Block S140; detecting an optical fiducialarranged on the aircraft in the sequence of optical images in BlockS142; calculating offset distances from a latch 130 on the tram 100 to alatch receiver on the aircraft based on the optical fiducial detected inthe sequence of optical images in Block S144; in response to an offsetdistance from the latch 130 to the latch receiver falling below athreshold distance, transitioning from adjusting power output of thedrivetrain 120 in Block S150 to sequentially arrive at tram waypoints inthe predefined sequence of tram waypoints concurrent with arrival of theaircraft at corresponding aircraft waypoints in the predefined sequenceof aircraft waypoints to adjusting output power of the drivetrain 120and adjusting a position of the latch 130 on the tram 100 based onpositions of the optical fiducial detected in optical images recorded bythe optical sensor 150; in response to contact between the latch 130 andthe latch receiver, triggering the latch 130 to engage the latchreceiver in Block S160; and, in response to the latch 130 engaging thelatch receiver, decelerating the aircraft in Block S170.

8.1 Waypoints

In Block S110, the remote computer system can assign a known airport toan aircraft, assign a known runway at the airport to the aircraft, andqueue a landing routine for the aircraft at the runway. The remotecomputer system can then generate a sequence of aircraft waypointsdefining a target approach of the aircraft toward the runway to initiatethe landing routine. For example, the remote computer system can accessa generic predefined approach path, access a predefined approach pathspecific to a type of the aircraft, calculate a custom approach path forthe aircraft, such as based on a type, weight, stall speed, liftcoefficient, etc. of the aircraft and based on local wind and weatherconditions near the runway. The predefined approach path can specify asequence of aircraft freedom waypoints for landing at the assignedrunway, wherein each waypoint specifies target geospatial latitude,geospatial longitude, altitude, pitch, yaw, and roll values and a targetspeed for the aircraft. In this example, the waypoints can be linearlyoffset, such as by ten meters along the predefined approach path linearor offset by a distance proportional to a distance from the aircraft tothe tram 100. The remote computer system can upload these aircraftwaypoints to the aircraft in Block S110, such as prior to takeoff oronce the runway and approach path are assigned to the aircraft, as shownin FIG. 4 .

In Block S112, the remote computer system can similarly access apredefined tram path or calculate a custom tram path for the tram 100based on the approach path selected or calculated for the aircraft inBlock S110. The predefined tram path can specify a sequence of tramwaypoints, wherein each tram waypoint specifies: global targetgeospatial latitude and longitude values for the tram 100; a globaltarget speed for the tram 100; and local altitude, pitch, yaw, and/orroll values for the dock on the tram 100. Each tram waypoint in thesequence of tram waypoints can be linked (i.e., mapped) to and executedsynchronously with one aircraft waypoint in the sequence of aircraftwaypoints. In particular, the remote computer system can interface withboth the aircraft and the tram 100 to achieve synchronicity between theaircraft and the tram 100 such that the tram 100 reaches a first tramwaypoint in the sequence of tram waypoints when the aircraft reaches acorresponding aircraft waypoint in the sequence of aircraft waypoints,as described below. The remote computer system can upload these tramwaypoints to the tram 100 in Block S112, such as once the tram 100 isqueued to receive the aircraft at the assigned runway, as shown in FIG.4 .

8.2 Approach

In preparation for the landing cycle, the remote computer system cansend a prompt to the tram 100 to navigate to the first tram waypoint—inthe sequence of tram waypoints—at the head of the runway in Block S120;the tram 100 can then implement autonomous ground-based navigationtechniques to navigate to the first waypoint.

To begin the landing routine, the aircraft can navigate to an initialaircraft waypoint (e.g., one mile ahead of the runway) and thenimplement autonomous flight control methods (e.g., autopilot techniques)to navigate through the remaining sequence of waypoints. For example, asthe aircraft approaches the runway, an autopilot system in the aircraftcan: track the 3D geospatial location (e.g., latitude, longitude, andaltitude), 3D orientation (e.g., pitch, yaw, and roll), and speed, etc.of the aircraft through a geospatial location sensor integrated into theaircraft, such as relative to fixed ground-based geospatial locationsensors; calculate differences between the actual 3D geospatiallocation, actual 3D orientation, and actual speed of the aircraft andcorresponding target values specified in the aircraft waypoints; andimplement closed-loop controls to adjust various flight surfaces andengine power to reduce these differences upon arrival at a next aircraftwaypoint.

8.3 Tram Trigger

In Block S122, the remote computer system triggers the tram 100 toexecute the sequence of tram waypoints in response to detecting arrivalof the aircraft at a trigger waypoint preceding the runway, as shown inFIG. 4 . In particular, the remote computer system can trigger the tram100 to rapidly accelerate to a landing speed of the aircraft and toreach this landing speed—matched to the speed of the aircraft—atapproximately the same time that the aircraft reaches an altitude atwhich the alignment receiver on the aircraft is accessible to (e.g.,within a minimal distance from) the alignment feature 132 in order tolimit a length of the runway traversed by the tram 100 before engagementwith the aircraft during the landing routine.

For example, the remote computer system can define an aircraft triggerwaypoint 2,400 feet ahead of the first tram waypoint and then triggerthe tram 100 to execute the sequence of tram waypoints once the aircraftreaches the trigger aircraft waypoint. In particular, in this example,the remote computer system can trigger the tram 100 to execute thesequence of tram waypoints when the aircraft reaches a distance from thestopped tram equivalent to an approximate distance covered by theaircraft traveling at a speed specified in subsequent aircraft waypoints(e.g., ˜170 to ˜157 mph) over a period of time needed by the tram 100 toaccelerate to the landing speed (e.g., 7.8 seconds) summed with thedistance covered by the tram 100 accelerating to the landing speed inthis period of time.

(Alternatively, the foregoing methods and techniques can be executedlocally by a local controller 160 within the tram 100, a localcontroller in the aircraft, or by a controller distributed between thetram 100 and the aircraft. For example, the tram 100 can establish awireless local or network connection with aircraft and the aircraftapproaches the runway, the tram 100 and aircraft can share geospatialand motion data over this wireless connection directly throughout thelanding routine, and the controller 160 can execute Block S122 locally.)

Once triggered by the remote computer system, the controller 160 canimplement autonomous navigating techniques and closed-loop controls tomodulate power supplied to motors (or other actuators) in the drivetrain120 to execute the sequence of tram waypoints in Block S130. Inparticular, the controller 160 can: receive a sequence of confirmationsof arrival of the aircraft at its assigned aircraft waypoints via thewireless communication module 152 described above; and then implementclosed-loop controls to adjust speed of the drivetrain 120 tosequentially arrive at each tram waypoint—in the predefined sequence oftram waypoints—along the runway concurrent with receipt of confirmationsof arrival of the aircraft at corresponding aircraft waypoints in thepredefined sequence of aircraft waypoints.

8.4 Local Optical Location

As described above, the controller 160 in the tram 100 can recordoptical images of a sky region above the tram 100 through one or moreoptical sensors, such as from initiation of the landing routine, frominitial motion of the tram 100 from the first waypoint, or once the tram100 reaches a trigger tram waypoint corresponding to a predicteddistance from the aircraft to the tram 100 for which an optical fiducialon the aircraft is reliably detectable in the fields of view of theoptical sensors. The controller 160 can then implement methods andtechniques described above to locally process these optical images todetermine a real 3D position and 3D orientation (e.g., x, y, and zoffset and pitch, yaw, and roll angles) of the aircraft relative to thetram, as shown in FIG. 4 .

For example, the controller 160 can implement methods and techniquesdescribed above to transform optical images recorded by the opticalsensors into lateral, longitudinal, and vertical offset distances andpitch, yaw, and roll offset angles between an alignment receiver on theaircraft and a corresponding alignment feature 132 on the tram 100. Inthis example, the controller 160 can implement a known pattern ofoptical fiducials on the aircraft and known distances between theseoptical fiducials: to determine a relative pitch angle of the aircraftbased on a fore-aft skew of optical fiducials detected in opticalimages; to determine a relative roll angle of the aircraft based onleft-right skew of optical fiducials detected in optical images; todetermine a vertical distance between the aircraft and the tram 100based on proximity of optical fiducials detected in optical images; todetermine relative yaw angle of the aircraft based on angular alignmentof the pattern of optical fiducials detected in optical images to theanteroposterior axis of the tram 100; to determine relative lateraloffset of the aircraft based on linear alignment of the pattern ofoptical fiducials detected in optical images to the anteroposterior axisof the tram 100; and to determine a relative longitudinal offset of theaircraft based on linear alignment of the pattern of optical fiducialsdetected in optical images to the lateral axis of the tram 100.

Once the controller 160 determines that an offset distance (e.g., avertical distance or nearest distance) from the latch 130 to the latchreceiver (or from the alignment feature 132 to the alignment receiver)is less than a threshold distance, such as based on an offset distanceextracted from optical images and/or based on waypoints last occupied bythe aircraft and the tram 100, the controller 160 can transition tocontrolling the speed of the tram 100 and the position of the motionplatform 134 based on a relative position and orientation of theaircraft extracted from optical data recorded through optical sensors inthe tram 100.

In one variation, the tram 100 can additionally or alternatively includesimilar optical fiducials, such as patterned across length and width ofits top or patterned directly over the aircraft dock; and the aircraftcan similarly include an optical sensor facing downwardly from itsfuselage and a local controller that implements similar methods andtechniques to locate the tram 100 relative to the aircraft. In thisvariation, the local controller in the aircraft can interface with thecontroller 160 in the tram 100 via a local wireless connection toconfirm—substantially in real-time—positions and orientations of theaircraft relative to the tram 100 calculated by the controller 160 inthe tram 100. The controller 160 can then merge, average, or otherwisecombine position and orientation data generated locally on the tram 100and remotely on the aircraft to calculate a next speed of the tram 100and a next position of the motion platform 134 as the aircraft descendsfurther toward the tram 100.

8.5 Engagement

The tram 100 can also include sensors in the alignment features todetermine when the alignment features have fully engaged theircorresponding alignment receivers in the aircraft; the aircraft cansimilarly include sensors in its alignment receivers to determine whenthe alignment receivers in the aircraft have fully received theircorresponding alignment features on the tram 100. Once the controller160 detects engagement between the alignment features and theiralignment receivers—and once the controller 160 receives confirmation ofthis engagement from the aircraft—the controller 160 can trigger thelatch 130 to engage the latch receiver on the aircraft in Block S160, asshown in FIG. 4 .

Once the latch 130 has engaged the latch receiver, the controller 160can: trigger the telescoping boom 136 to retract; trigger the cradlepoints 142 to extend out to meet corresponding hard points in theaircraft; and then trigger the drivetrain 120 to (rapidly) deceleratethe tram 100 and the aircraft in Block S170. For example, for theaircraft that includes reverse thrusters, the controller 160 in theaircraft can coordinate with the aircraft (e.g., directly over a wiredor wireless connection) to simultaneously trigger the drivetrain 120 toenter a braking mode and to actuate the reverse thrusters in theaircraft. Alternatively, the controller 160 can trigger the aircraft tocut its engines once the latch 130 has engaged the latch receiver inpreparation for the drivetrain 120 decelerating the tram 100 and theaircraft.

However, the tram 100 can cooperate with the aircraft and the remotecomputer system in any other way to execute a landing process.

9. Taxiing Process

Once the tram 100 has decelerated the aircraft to a taxiing speed, suchas independently or in cooperation with the aircraft, the tram 100 canimplement autonomous ground-based navigating techniques to deliver theaircraft to a gate assigned to the aircraft, such as by the remotecomputer system. For example, the tram 100 can navigate along apredefined route from the terminus of the runway to the assigned gate.

Once the aircraft is unloaded, reloaded, and refueled at the gate andthen queued by the remote computer system for takeoff from an assignedrunway, the remote computer system can serve a prompt to the tram 100 toreturn to the landing end of the assigned runway in Block S180; and thetram 100 can then autonomously navigate to the assigned runway, such asalong a predefined route from the gate to the head of the runway inpreparation for a next takeoff cycle in Block S182, as shown in FIG. 5 .For example, the tram 100 can include a suite of laser or other opticalbased sensors and can implement autonomous navigation techniques toautonomously navigate along taxi routes and to avoid collisions withother trams and aircraft on the tarmac based on outputs of thesesensors.

10. Takeoff Routine

In one variation shown in FIG. 5 , the tram 100 interfaces with theremote computer system and the aircraft to execute a takeoff routine. Inthis variation, once the tram 100 arrives at the head of the runway andthe remote computer system clears the aircraft for takeoff, the remotecomputer system serves confirmation for a takeoff routine to theaircraft and to the tram 100 in Block S190. The tram 100 can then querythe aircraft for confirmation of a system check, such as via a wired orlocal wireless connection, as described above, in Block S192. Inresponse to receipt of such confirmation (and following its own internalsystems check), the tram 100 can: assume a master control; issue aprompt to the aircraft to set its engines at maximum speed in BlockS194; and substantially simultaneously trigger the drivetrain 120 toaccelerate down the runway to a takeoff speed in Block S196.

Alternatively, the aircraft can assume master control and issue commandsto the tram 100 to accelerate down the runway. For example, the remotecomputer system can transmit confirmation for the takeoff routine to thetram 100 and to the aircraft to arm the tram 100 and the aircraft forautonomous takeoff. Once it has autonomously completed a final systemscheck, the aircraft can transmit a takeoff trigger to the tram 100 andset its engines to full power. Upon receipt of the takeoff trigger fromthe aircraft, the controller 160 can set the drivetrain 120 to full (orincreased) power to cooperate with the aircraft to accelerate to atakeoff speed, such as a generic takeoff speed specified for a type ofthe aircraft or calculated based on a laden weight of the aircraftmeasured by the tram 100, as described above.

While accelerating, the tram 100 can also cooperate with the aircraft toremain centered on the runway, such as by executing a sequence oftakeoff waypoints centered along the runway or by following a lanemarker along the runway.

Once the aircraft reaches the takeoff speed, the controller 160 cantrigger the latch 130 to release the latch receiver and trigger thetelescoping boom 136 and cradle points 142 to retract into the chassis100 in Block S198, such as to reduce risk of damage to the fuselage ofthe aircraft. Alternatively, as the tram 100 and aircraft accelerate,the controller 160 can additionally or alternatively sample a straingauge or tension sensor in the latch 130, motion platform 134, ortelescoping boom 136, etc. to determine a level of lift induced by theaircraft's wings as the aircraft accelerates. Once the level of liftcreated by the aircraft exceeds a preset threshold, the controller 160can trigger the latch 130 to release, etc. Yet alternatively, thecontroller 160 can delay release of the latch 130, etc. until both thetakeoff speed is reached and lift created by the aircraft exceeds thepreset threshold.

Once the latch 130 is released in Block S198 and as the aircraft beginsto separate from the tram 100, the controller 160 can continue tomonitor distances from the aircraft to the tram 100 based on opticalfiducials—on the aircraft—detected in optical images recorded by theoptical sensor 150 in the tram 100 during the takeoff routine. (Thecontroller 160 can additionally or alternatively monitor distances fromthe aircraft to the tram 100 based on geospatial locations recorded bygeospatial location sensors in the tram 100 and the aircraft.) Once thedistance between the aircraft and the tram 100 exceeds a presetthreshold (e.g., once the aircraft has ascended sufficiently above thetram 100, such as two meters), the controller 160 can trigger thedrivetrain 120 to rapidly decelerate the tram 100 before reaching theterminus of the runway.

The controller 160 can then navigate the tram 100 to a holding area orreturn directly to the head of the runway in preparation to execute anext landing routine with another aircraft according to methods andtechniques described above.

The systems and methods described herein can be embodied and/orimplemented at least in part as a machine configured to receive acomputer-readable medium storing computer-readable instructions. Theinstructions can be executed by computer-executable componentsintegrated with the application, applet, host, server, network, website,communication service, communication interface,hardware/firmware/software elements of a user computer or mobile device,wristband, smartphone, or any suitable combination thereof. Othersystems and methods of the embodiment can be embodied and/or implementedat least in part as a machine configured to receive a computer-readablemedium storing computer-readable instructions. The instructions can beexecuted by computer-executable components integrated bycomputer-executable components integrated with apparatuses and networksof the type described above. The computer-readable medium can be storedon any suitable computer readable media such as RAMs, ROMs, flashmemory, EEPROMs, optical devices (CD or DVD), hard drives, floppydrives, or any suitable device. The computer-executable component can bea processor but any suitable dedicated hardware device can(alternatively or additionally) execute the instructions.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the embodiments of the invention without departing fromthe scope of this invention as defined in the following claims.

I claim:
 1. A tram system comprising: a chassis; a latch coupled to thechassis and configured to selectively engage a latch receiver mounted toan underside of a fuselage of an aircraft; an alignment feature:adjacent the latch; configured to selectively engage an alignmentreceiver mounted to the underside of the fuselage of the aircraft; andconfigured to communicate forces parallel to an anteroposterior axis ofthe chassis into the aircraft; a first optical sensor facing upwardlyfrom the chassis and configured to record a first sequence of opticalimages; a drivetrain configured to accelerate and decelerate the chassisalong a runway; a controller configured, during a landing routine: todetect a first optical fiducial arranged on the aircraft in the firstsequence of optical images recorded by the first optical sensor; toadjust a speed of the drivetrain to longitudinally align the firstalignment feature with the first alignment receiver on the aircraftduring descent of the aircraft toward the runway based on positions ofthe first optical fiducial detected in the first sequence of opticalimages; to trigger the latch to engage the latch receiver on theaircraft in response to descent of the first alignment receiver onto thefirst alignment feature; and to trigger the drivetrain to activelydecelerate the chassis and the aircraft in response to engagement of thelatch on the latch receiver.
 2. The system of claim 1: furthercomprising a communication module configured to communicate with theaircraft; wherein the controller is further configured to control thedrivetrain to navigate the chassis to a head of the runway during ataxiing routine; and wherein the controller is further configured,during a takeoff routine: to receive takeoff confirmation from theaircraft via the communication module; to trigger the drivetrain toaccelerate down the runway concurrently with acceleration of engines inthe aircraft in response to receipt of takeoff confirmation from theaircraft; and to trigger the latch to release the latch receiver on theaircraft in response to a velocity of the chassis exceeding a takeoffspeed assigned to the aircraft.
 3. The system of claim 1: furthercomprising a rail follower extending from the chassis, configured toengage a power rail integrated into the runway, and configured to sourceelectrical power from the power rail; and wherein the drivetrain:comprises a set of electric motors configured to drive a set of wheelsto accelerate the chassis; configured to source power from the powerrail via the rail follower to power the set of electric motors; andoperable in a generator mode to feed energy back into the power rail viathe rail follower to actively decelerate the chassis and the aircraft inresponse to engagement of the latch on the latch receiver during thelanding routine.
 4. The system of claim 3: further comprising a powercoupling adjacent the latch and configured to engage a power receptacleon the underside of the fuselage of the aircraft; wherein the controlleris configured to trigger the rail follower to retract from the powerrail in response to conclusion of the landing routine; and wherein thedrivetrain is configured to source power from the aircraft via the powercoupling, during navigation from the terminus of the runway to a gate inan airport assigned to the aircraft, following retraction of the railfollower from the power rail.
 5. The system of claim 1: furthercomprising a rail follower: extending from the chassis; configured toengage a power rail integrated into the runway; and comprising anelectromagnetic element configured to face the power rail; and whereinthe drivetrain comprises a set of electric motors: configured to drive aset of wheels under the chassis; operable in a motor mode to sourcepower from the power rail via the rail follower to accelerate thechassis prior to engagement of the latch during the landing routine; andoperable in a generator mode to feed energy to the electromagneticelement on the rail follower to induce Eddy currents in the power railto slow the chassis and the aircraft following engagement of the latchduring the landing routine.
 6. The system of claim 1: further comprisinga rail follower: extending from the chassis; configured to engage anundercut linear rail extending longitudinally along the runway; andconfigured to communicate lateral forces into the rail to maintain alateral position of the chassis along the runway during the landingroutine; further comprising a lateral adjustment subsystem coupling thelatch and the first alignment feature to the chassis; and wherein thecontroller is configured to adjust a position of the lateral adjustmentsubsystem to align the first alignment feature to the first alignmentreceiver on the aircraft by maintaining the first optical fiducialproximal a first target position in the first sequence of optical imagesas the aircraft approaches the runway during the landing routine.
 7. Thesystem of claim 1: further comprising a wireless communication modulecoupled to the controller; further comprising a geospatial locationsensor coupled to the controller and configured to interface with aremote computer network to calculate a geospatial location of thechassis; wherein the controller: interfaces with the drivetrain tonavigate the chassis at a first tram waypoint defining a firstgeospatial location proximal a head of the runway in preparation for thelanding routine; and triggers the drivetrain to accelerate the chassisdown the runway in response to a receipt of confirmation of arrival ofthe aircraft at a first aircraft waypoint ahead of the runway via thewireless communication module.
 8. The system of claim 7: wherein thewireless communication module receives a sequence of confirmations ofarrival of the aircraft at a predefined sequence of aircraft waypoints;and wherein the controller implements closed-loop controls to adjustspeed of the drivetrain to sequentially arrive at each tram waypoint ina predefined sequence of tram waypoints along the runway concurrent withreceipt of confirmations of arrival of the aircraft at correspondingaircraft waypoints in the predefined sequence of aircraft waypoints. 9.The system of claim 8, wherein the controller: calculates offsetdistances from the first alignment feature to the first alignmentreceiver on the aircraft based on distances between the first opticalfiducial and a second optical fiducial detected in the first sequence ofoptical images; and in response to an offset distance from the firstalignment feature to the first alignment receiver on the aircraftfalling below a threshold distance, transitions from implementingclosed-loop controls to adjust speed of the drivetrain to sequentiallyarrive at tram waypoints in the predefined sequence of tram waypointsconcurrent with receipt of confirmations of arrival of the aircraft atcorresponding aircraft waypoints in the predefined sequence of aircraftwaypoints to implementing closed-loop controls to adjust speed of thedrivetrain and a position of the first alignment feature relative to thechassis based on positions of the first optical fiducial detected inoptical images recorded by the first optical sensor.
 10. The system ofclaim 1: further comprising a telescoping boom coupling the latch andthe first alignment feature to the chassis configured to raise the latchand the first alignment feature above the chassis to meet the aircraftduring the landing routine; and a cradle comprising a set of cradlepoints configured to contact and support corresponding hard pointsdefined across the underside of the fuselage and wings of the aircraft;and wherein the controller: extends the telescoping boom upward to matethe first alignment feature to the first alignment receiver on theaircraft during descent of the aircraft; and retracts the telescopingboom to draw the aircraft into the cradle and to mate the set of cradlepoints in the cradle to hard points defined across the aircraft inresponse to engagement of the latch with the latch receiver.
 11. Thesystem of claim 10: wherein each cradle point, in the set of cradlepoints, is mounted to a retractable pin in a set of retractable pinscoupled to the chassis; wherein the set of retractable pins is arrangedon the chassis in an array corresponding to a generic arrangement ofhard points on the aircraft; wherein the controller is configured,during the landing routine: to access a database of vertical positionsof hard points arranged across the aircraft; and to extend the set ofretractable pins according to the database of vertical positions inorder to engage each cradle point, in the set of cradle points, tocorresponding hard points on the aircraft.
 12. The system of claim 10,wherein the controller is further configured, during a takeoff routine:to unlock the telescoping boom to permit the aircraft to ascend off ofthe cradle; to trigger the latch to release the latch receiver inresponse to extension of the telescoping boom to a threshold heightabove the chassis; and to maintain forward acceleration of the chassisvia the drivetrain to communicate forward force into the aircraft viathe telescoping boom and the first alignment feature following releaseof the latch from the latch receiver.
 13. The system of claim 1: whereinthe first alignment feature defines an external frustoconical sectionconfigured to mate with the first alignment receiver defining aninternal frustoconical section in the aircraft; wherein the latchcomprises: a set of bearings arranged in captured bores in the firstalignment feature; and an expansion driver: running inside the firstalignment feature; operable in an advanced position to expand the set ofball bearings outwardly into engagement with a shoulder defining thefirst latch receiver inside the first alignment receiver; and operablein a retracted position to release the ball bearings from the shoulder;and wherein the controller is configured: to trigger the expansiondriver to transition into the advanced position to lock the set of ballbearings to the shoulder in response to descent of the first alignmentreceiver onto the first alignment feature during the landing routine;and to trigger the expansion driver to transition into the retractedposition to unlock the set of ball bearings from the shoulder inresponse to acceleration of the chassis and the aircraft to a takeoffspeed assigned to the aircraft during a takeoff routine succeeding thelanding routine.
 14. The system of claim 1: further comprising a motionplatform supporting the first alignment feature on the chassis; whereinthe first optical sensor is arranged on the motion platform adjacent thefirst alignment feature; further comprising: a second alignment featurearranged on the motion platform and offset from the first alignmentfeature; a third alignment feature arranged on the motion platform andoffset from the first alignment feature and the second alignmentfeature; a second optical sensor arranged on the motion platformadjacent the second alignment feature; a third optical sensor arrangedon the motion platform adjacent the third alignment feature; wherein thecontroller adjusts a speed controller and a braking system in thedrivetrain and adjusts a position of the motion platform relative to thechassis to: maintain the first optical fiducial proximal a first targetposition in a first field of view of the first optical sensor, maintaina second optical fiducial proximal a second target position in a secondfield of view of the second optical sensor, and maintain a third opticalfiducial proximal a third target position in a third field of view ofthe third optical sensor from a time that the aircraft is within athreshold distance of the chassis until the first alignment featureengages the first alignment receiver in the aircraft, the secondalignment feature engages a second alignment receiver in the aircraft,and the third alignment feature engages a third alignment receiver inthe aircraft.
 15. The system of claim 14: wherein the first opticalsensor is configured to detect infrared light at a first wavelengthbroadcast by the first optical fiducial on the aircraft; wherein thesecond optical sensor is configured to detect infrared light at a secondwavelength broadcast by the second optical fiducial on the aircraft, thesecond wavelength different from the first wavelength; wherein the thirdoptical sensor is configured to detect infrared light at a thirdwavelength broadcast by the third optical fiducial on the aircraft, thethird wavelength different from the first wavelength and the secondwavelength; wherein the motion platform comprises a gimbal; and whereinthe controller, during the landing routine: calculates a pitch angleoffset, a yaw angle offset, and a roll angle offset of the aircraftrelative to the gimbal based on a first position of infrared lightdetected in a first optical image in the first sequence of opticalimages, a second position of infrared light detected in a second opticalimage in a second sequence of optical images recorded by the secondoptical sensor, and a third position of infrared light detected in athird optical image in a third sequence of optical images recorded bythe third optical sensor; and implements closed-loop controls to adjusta pitch angle, a yaw angle, and a roll angle of the gimbal to reduce thepitch angle offset, the yaw angle offset, and the roll angle offset ofthe aircraft.
 16. The system of claim 1: further comprising a frontgimbal arranged proximal a front of the chassis; further comprising arear gimbal arranged proximal a rear of the chassis; wherein the latchis arranged on the front gimbal and is configured to selectively engagea latch receiver arranged proximal a front of the fuselage of theaircraft; wherein the first alignment feature is arranged on the frontgimbal adjacent the latch and is configured to selectively engage thefirst alignment receiver arranged proximal the front of the fuselage ofthe aircraft; further comprising a second latch arranged on the reargimbal and is configured to selectively engage a rear latch receiverarranged proximal a rear of the fuselage of the aircraft; furthercomprising a rear alignment feature: arranged on the rear gimbaladjacent the rear latch; configured to selectively engage a rearalignment receiver arranged proximal the rear of the fuselage of theaircraft; and configured to cooperate with the first alignment featureto communicate forces parallel to the anteroposterior axis of thechassis into the aircraft; and wherein the controller is configured,during the landing routine: to independently adjust lateral positions ofthe front gimbal and the rear gimbal to accommodate a yaw angle of theaircraft in the presence of a headwind during approach of the aircrafttoward the runway by aligning the first alignment feature with the firstalignment receiver on the aircraft and aligning the rear alignmentfeature with the rear alignment receiver on the aircraft.
 17. The systemof claim 16, wherein the controller is configured to release locks onthe front gimbal and the rear gimbal to accommodate a change in yawangle of the aircraft in the presence of a headwind acceleration of theaircraft to takeoff speed during a takeoff routine.
 18. A methodcomprising: assigning a sequence of aircraft waypoints along a landingapproach path and along a runway at an airport to an aircraft; assigninga sequence of tram waypoints along the runway to a tram; prompting thetram to navigate to a first tram waypoint, in the sequence of tramwaypoints, at a head of a runway in preparation for a landing routine;in response to the aircraft reaching a trigger waypoint, in the sequenceof aircraft waypoints, preceding the runway, triggering the tram toaccelerate to a landing speed of the aircraft; at the tram: adjustingoutput power of a drivetrain in the tram to sequentially arrive at eachtram waypoint in the sequence of tram waypoints concurrent with arrivalof the aircraft at corresponding aircraft waypoints in the sequence ofaircraft waypoints; recording a sequence of optical images through anoptical sensor arranged on the tram; detecting an optical fiducialarranged on the aircraft in the sequence of optical images; calculatingoffset distances from a latch on the tram to a latch receiver on theaircraft based on the optical fiducial detected in the sequence ofoptical images; in response to an offset distance from the latch to thelatch receiver falling below a threshold distance, transitioning fromadjusting power output of the drivetrain to sequentially arrive at tramwaypoints in the predefined sequence of tram waypoints concurrent witharrival of the aircraft at corresponding aircraft waypoints in thepredefined sequence of aircraft waypoints to adjusting output power ofthe drivetrain and adjusting a position of the latch on the tram basedon positions of the optical fiducial detected in optical images recordedby the optical sensor; in response to contact between the latch and thelatch receiver, triggering the latch to engage the latch receiver; andin response to the latch engaging the latch receiver, decelerating theaircraft.
 19. The method of claim 18: wherein decelerating the aircraftcomprises decelerating the aircraft to a taxiing speed; and furthercomprising: assigning a gate of the airport to the tram; at the tram,autonomously navigating, with the aircraft in tow, to the gate inresponse to decelerating the aircraft to the taxiing speed.
 20. Themethod of claim 19, further comprising: prompting the tram toautonomously navigate, with the aircraft in tow, from the gate to thehead of the runway in preparation for a takeoff routine; transmittingconfirmation for the takeoff routine to the aircraft and to the tram; atthe tram: in response to receiving confirmation for the takeoff routineand receiving system confirmation from the aircraft, accelerating downthe runway to a takeoff speed of the aircraft; in response to reachingthe takeoff speed, releasing the latch from the latch receiver torelease the aircraft from the tram; decelerating in response to anoffset distance between the latch and the latch receiver exceeding atakeoff threshold distance.